Humanoid Synthetics have become an inextricable part of society, obediently serving and protecting the human population. But what happens when these Synths are given the right to consciousness and their own free will?

The second season picks up several months after the events of Season 1, with Niska (Emily Berrington) still at large and in possession of the consciousness code. Her Synth family, Mia (Gemma Chan), Leo (Colin Morgan) and Max (Ivanno Jeremiah), unaware of her location, are each trying to find their place in the world, while Joe (Tom Goodman-Hill) and Laura (Katherine Parkinson) attempt to mend their marriage.

As unconfirmed reports of Synths behaving inexplicably surface, the ripple effects of one simple yet seismic decision sees the past return dramatically and surprisingly to the door of the Hawkins house. Joe, Laura and the entire family are faced with a difficult choice that will put the family under an intense spotlight.